Pavement



(No Model.)

Y C. o. GILMAN.

PAVEMENT.

No. 338,511. Patented Mar. 23, 1886.

UNrTnD STATES Param. OFFICE.

CHARLES CARROLL GILMAN, OF ELDORA, IOVA.

PAVEMENT.

SPECIFICATION forming part of Letters Patent No. 338,511, dated March 23, 1886. Application tiled April 1-1, 18Sv5. Serial No. 162,217. (No model.)

To all whom, t may concern:

Be it known that I, CHARLES CARROLL GIL- way or sidewalk formed of slabs or blocks of terra cotta lumber or porous burned brick material saturated or impregnated with asphaltum.

In the accompanying drawings, which form a part of this specification Figure 1 represents a cross-section of' a pavement embodying my invention, in which the surface-layer consists of wood blocks. Fig. 2 represents a surfacelayer of mastic, combined with a foundation of blocks of terra-cotta lumber treated as described. Fig. 3 represents a modification in which the foundation is composed of two layers of slabs arranged to break joint with each other, and Fig. 4 illustrates another modification in which the slabs or blocks are offset and overlap each other.

The foundation illustrated in Fig. l consists of slabs or blocks A, of terra-cotta lumber or porous burned-brick material, of a size varying from two to sin, but preferably three, inches in thickness, about twelve inches wide, and from sixteen to thirty inches long. Said slabs or blocks are saturated or impregnated with asphaltum.

In order to thoroughly im pregnate the slabs of said material with the asphaltum, I place the former in a closed tube, vessel, or receiver, from which I exhaust the air, and then admit thereto the hot melted asphaltum, the same being forced by the atmospheric pressure into the pores or cells (exhausted of air) of the terra-cotta lumber, the latter being heated to about the same temperature as the said asphaltum, to avoid chilling the latter.

The method just described is similar to the Well-known process employed in impregnating wood with creosote, and since no claim is laid to said method a fuller description thereof is not essential to an understanding of this invention. The saturated terracotta lumber, after it has cooled and the asphaltum hardened or become solid, is, in fact, a new material, which is much stronger and of greater weight than the uuimpregnated material, is absolutely impervious to moisture, cannot decay, and is practically.indestructible. The said slabs or blocks, treated as described, are laid on a sub-foundation of sand or gravel, B, and on said slabs as a foundation the blocks of wood C are placed, in the usual manner. Instead of a wooden pavement being laid on said foundation, blocks of Astone may be substituted as a surface-layer.

In Fig. 2 the blocks of impregnated terracotta lumber, A', are of greater depth or thickness than the slabs shown in Fig. l. They are preferably from six to eight inches in depth, and from eight to twelve inches wide and long, and the surface thereof is covered with a mastic, D, composed ofasphalt, gravel, and pounded limestone. This mastic is rolled over the same to a thickness of, say, three inches, (more or less,) varying according to circumstances.

For sidewalks, the dimensions of the blocks used and the thickness of the coating of mastic applied thereto would be less than for roadways.

In Fig. 2 I .have also shown foundationblocks A2, having inclined sides-that is to say, of tapering form-so as to secure a bearing of the blocks on each other, and these are laid as illustrated in said figure.

To retain the sand of the sub-foundation in place, the under side of the blocks or slabs may be made concave, as shown at E, Fig. 2.

Instead of constructing the foundation of one. layer of said slabs, it may consist of two layers arranged to break joint with each other, as illustrated in Fig. 3; or the blocks or slabs A3 may be offset on opposite sides, so that when laid together they will overlap each other, as illustrated in Fig. 4.

AIn lieu of the mastic, hereinbefore referred to, a bedding or layer of cement may be applied to the surface of the saturated terra-cottalumber blocks. Such a construction is particularly adapted for sidewalks and for cold climates, being less liable to crack than the said mastic. l

IOO

I am aware that ordinary building-bricks have been immersed in a liquid solution of alum, boraX, copperas, and Water, and after drying boiled in a mixture of caoutchouc and coal-tar, and that it has been proposed to use such bricks as the surface-layer of a pavement or sidewalk. I am also aware that it has been proposed to lay a surface-layer of terracotta blocks upon a foundation of bricks, and also that it is not new to eure a brick by immersion in a mixture of coal-tar, bitumen, pine-gum, and alum, and these several things I do not claim.

Having thus described my invention, What I desire to claim and secure by Letters Patent 1sl. A pavement consisting of a surface-layer of material7 substantially as described7 and a foundation composed of slabs or blocks of ter- Ia-cotta lumber saturated or completely impregnated With asphaltum, substantially as set forth.

2. A pavement consisting of a surface-layer of paving-blocks and a foundation composed of slabs or blocks of terracotta lumber satu- 2 5 rated or completely impregnated With asphaltum, substantially as described.

3. Apaverncnt consisting of a surface-layer of wood paving-blocks and'a foundation composed of slabs or blocks of terra-cotta lumber 3o of two layers of slabs or blocks of terra-cotta 35 lumber saturated or completely impregnated with asphaltum, the slabs of one layer being arranged to break joint With those ofthe other, substantially as described.

In testimony whereoi'l have signed my name 4o in the presence of two Witnesses.

CHARLES CARROLL GILMAN.

Witnesses:

RnUBnN B. GALUsHn, EDMUND RICE. 

